1. Field of the Invention
The present invention relates to a surge absorber.
2. Related Background Art
Semiconductor devices such as ICs and LSIs can be broken or deteriorated in characteristics by static electricity of high voltage. For this reason, the semiconductor devices are constructed using a surge absorber, such as a varistor, as a countermeasure against static electricity.
Incidentally, the surge absorbers including the varistors have a stray capacitance component and a stray inductance component. Therefore, if a surge absorber is applied to a circuit handling high-speed signals, it will deteriorate the high-speed signals. The stray capacitance component of the surge absorber must be kept small for applying the surge absorber to the circuit handling high-speed signals; otherwise, deterioration will inevitably occur in rising characteristics and delay characteristics of the high-speed signals. However, decrease of the stray capacitance component of the surge absorber will result in increase of control voltage of the surge absorber and decrease of energy resistance of the surge absorber.
A surge absorber provided with an inductor and two varistors is known as a surge absorber for alleviating the influence of the stray capacitance component (e.g., Japanese Patent Application Laid-Open No. 2001-60838). The surge absorber described in the Laid-Open No. 2001-60838 has a parallel circuit consisting of the first varistor and the inductor, the second varistor electrically connected in series to the parallel circuit, and input/output electrodes and a ground electrode connected to the two ends of the series circuit consisting of the second varistor and the parallel circuit.